Railway traffic controlling system



July 28, 1936. R. M. PHINNEY RAILWAY TRAFFIC CONTROLLING SYSTEM Filed Ja n. 15, 1951 I T AL INVENTO I 7 7$. C?

ATTORNEY nm F N m:

Illllltlllill lll I ll Cal Patented July 28, 1936 PATENT OFFICE RAILWAY TRAFFIC CONTROLLING SYSTEM Robert M. Phinney, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application January 15, 1931, Serial No. 508,922

16 Claims.

This invention relates'to railway traflic controlling systems, and more particularly to a system of the unit line wire type, as distinguished from a system of the selector type.

In accordance with the present invention, it is proposed to control a switch machine at a distant track switch in accordance with the polarity of current applied to one line circuit and to set up a direction of traific over said track switch in accordance with the polarity applied to another line circuit, and to indicate over. these two circuits the operation of the switch machine, the condition of detector track circuit occupancy and I whether or not all of the signals associated with said track switch are at stop. In order to accomplish these results, it is proposed to clear a signal over a line circuit and to open such line circuit as soon as such signal is clear, this signal being. held clear through suitable. stick arrangement; It thus becomes obvious that if the signal is once cleared it cannot be put to stop manually over this same line circuit, and in accordance with the present invention it is proposed to put such signal to stop manually over said another line circuit used for controlling. the

operation of the track switch.

Other objects, purposes and characteristic features of the invention will be in part. obvious from the accompanying drawing and will in part be more specifically pointed out hereinafter.

In describing the invention in detail, reference will be made to the single drawing, showing conventionally the trackway apparatus at one end of a distant passing siding, together with the central ofiice equipment for controlling and receiving indications from said trackway apparatus. Referring to the drawing the track rails I have been shown divided into blocks by insulating joints 2 to provide the usual track circuits, of which the detector track circuit containing the detector track relay DT and the battery 4 have been shown.

Although the invention may be applied to double track railroads, that is where traific moves only in one direction, it has been shown applied to a single track railway system preferably signalled by a signalling system of the absolute-permissive-block type, of which a portion of a single track section and a portion of a passing siding PS only have been illustrated. This passing siding PS includes a track switch SW operable through the medium of the switchmachine SM, and this track switch SW has associated therewith starting signals 1 and I for governing the entrance fromthe' main track andthe side track of the passing sidingprespectively, into the single tracksection O, and has also associated therewith an entering signal 8 and a take-siding signal 8 The switch machine SM is controlled by a polar 5 neutral relay WZ through suitable circuits conventionally shown by the dotted line 9. This switch machine is provided with contacts therein for controlling a polar switch machine repeater relay WP, which relay is energized only if the switch machine assumes its full normal or full reverse locked position, and is energized by current of positive polarity when the switch machine assumes its normal position and current of negative polarity when the switch machine assumes its reverse position. The signals 1, 1

8 and 8 are controlled through the medium of a polar neutral control relay $2, the direction of trafic being determined by the polar position of this signal control relay SZ, and the main track or side track signal is selected in accordance with the polar position of the switch machine repeater relay WP, providing this relay WP is in correspondence with the switch machine relay WZ. This switch machine repeater relay WP is energized through the following circuit:-beginning at the terminal or the terminal depending upon whether the switch is in its normal or reverse position, contact Ill, wire II or [2, wire l3, winding of the relay W? to the midpoint C of said battery.

A relay M is provided to indicate whether or not all of the signals 1, 1 8 and 8 assume the stop position, this relay being. energized through the following circuit-beginning at the terminal of a suitable battery, contact M of the signal 8, wire l5, contact l6 closed only when the signal 8 is in the stop position, wire 11,. contact l8 closed only when the signal 1 is in the stop position, Wire 19, contact 20 closed only when the signal 1 is in the stop position, wire 2|, winding of the relayM to the other'terminal of said battery.

The wayside apparatus also includes a relay OS which may be energized. by current of one or the other polarity depending upon .whether the relay WP is energized or deenergized, relay OS being energized through the following circuit:- beginning at the terminal' or terminal depending upon the condition of energization of the relay WP, contact 23 of the relay WP, wire 2.4, front contact 25 of the relay DT, wire 26, of therelay OS to the midpoint C. of said battery.

'In the central oflice DO, has been illustrated a which indicates through the medium of the relay OSR the initiation of operation of the switch machine and the completion of itsstroke and the occupancy of the detector track circuit associated with the track switch SW. ,The central oflice apparatus also includes twolever, repeating relays R and R the function of which is more readily described hereinafter.

Operation) 7 As shown in the drawing, the switch machine lever WL assumes its maintrack position, under which condition the relay W2 is. energized through the following circuit:beginning at the terminal of the central oifice split battery, wire contact of the lever WL, wire 3|, back contactBZ of the relay'R wires 33 and 34, back contact 350i the relay'R wires '36 and 31, winding of the relay OSR, line wire 38, front contact '39 of the-relay OS, wire 48, winding of the relay WZ through a suitable return wire C connected to the midpoint of the'oflice battery.

Y Let us now assume that there is an east bound train in the single track section and that the operator wishesthis train to proceed into the main track of this passing siding PS. to inform the engineer of the train of this fact the operator will, to effect energization of the relay SZ, move his lever SL' to the right, thereby closing the following circuit for the relay R beginning at theterminal of the central oifice battery, contact 42 of the lever SL, wire 43, winding of the relay R te the other terminal of said battery. The closure of this circuit will effect energization of the relay R, thereby closing the following circuit for the relay SZ:-begin- 'ning at the terminal of the central oflice battery, front contact 45 of the relay R wire 46, indicating relay SOS, line wire 41, front contact 48 of the relay M, wire 89, front contact 58 of the relay WZ, wirei'fil, winding of thevrelay SZ, to the common return wire'C connected to the midpoint'of the officebattery I v The completion of this circuit will energize the relaySZ to the right, thereby closing the clearing circuitfor the signal 8 which may be traced as follows:'beginning at the terminal of the way station battery, front contact 53 of the detector track relay DT, wire 54, front contact 55 of the relay SZ, wire 56, polar contact of the relay SZ to the right, wires 58 and 59, polar contact 89 of therelay WZ, wire 61, neutral contact 82 of the relay WZ, wire 83, neutral contact 64 of the relay WP, wire 65, polar contact 66 of-the relay WP, wire'filineutral contact 68 of the home relay 8H (controlled-in accordance with trafiic conditions in advance), wire 89, polar contact 18 of the-relay 8I-Ithrough the clear or caution wire, conventionally shown bythe dotted line H, depending on'traffic conditions in advance, through the mechanism of the signal 8 for operating this signal38 to. its clear position. Although these signalsl, 7 8 and 8 may be either light signals or semaphore signals they have for: convenience been illustrated as semaphore signals. With-the signal 8 assumingits clear or-c'auti'on In order position its contact i 8 is opened, thereby effecting deenergization of the relay M and causing the relay SZ to be energized through the following stick circuit:--beginning at the terminal of the way station split battery, polar contact 73 of the relay SZ, wire M, neutral contact 75 of the relay SZ, wire 76, back contact as of the relay M, wire 48, front contact 58 of relay WZ, wire 5i;

winding of the'relay SZ, to the midpoint C of the way station battery. It is thus noted that clearing of the signal 8effected' dropping of the con- 7 opening of the circuit for SOS at 48 and the dropcontact E9 of the relay R wire 88, indicating lamp E1, to the other terminal y of the central office battery. 3 r 7 Let us now assume that the east bound train under consideration moving in the single track section 0 accepts the signal 8, and proceeds into the main track of the passing siding PS; As the train in question treads upon the detector track the contact 39 in theenergizing circuit for the relay WZ which is slightly slowacting, so the relay WZ is not deenergized because the following stick circuit for this relay WZ is closed:- beginning at the terminal of the way station battery, polar contact 82 of the relay WZ, wire 83, front contact 84 of the relay WZ, wire 85, back contact 39 of therrelay OS, wire 40, winding of the relay WZ, to the midpoint C of the way station battery. Dropping of the contact .38 of the relay OS although it does not effect dropping of the relay WZ does effect deenergization of the indicating relay OSR, in the central ofiice DO, thereby completing the following energizing circuitrfor the detector track occu-, pancy indicator-.OSI:beginning at the terminal of the central ofiice battery, wire 30, switch machine lever WL, wire 3|, back contact 32 of the relay R wires 33 and 86, contact of the lever SL, wires'8l and 88, back contact 89 of the relay OSR, wire 98, indicating lamp lOSI, to the midpoint C of the central office battery. The operator is thus informed that the detector track circuit containing the track relay DT is occupied by the passing train.

Also, as heretofore pointed out the passage of the train by the signal 8 moves the signal 8 to its stop position by reason of the opening of the contact 53 of the detector track'relay DT. This movement-of the signal 8 to the stop position will of course reclose the energizing circuit for the signals-at-stop relay M, thereby effecting reenerg'ization of the indicating relay SOS and opening of its contact ll, whereby they east bound indicating lamp E1 is extinguished, informing the operator that 'the'formerly cleared east bound signal has'moved to its stop position. As soon as the rear end of the train passes off of the detector track circuitcontaining track relay DT, this relay DT'is reenergized, thereby effecting reenergization of the relayOS, which in turn effeets-reenergization of the indicating relay OSR and theextinguishmcn't of the indicating lamp OSI in the central office. i The east bound'signal lamp EI, will, however, not be reener'gi'zed at this time, because the signal 8--is nowheldat' stop by reason of deenergization of the home relay 8-H through the medium of the track relay T comprising part'of the track circuit for the main track of-the passing siding PS, and which is normally energized by the track battery 5. As soon as the train in question passes inan-eastwardly direction to an extent to permit energization of the home-relay 8H to its. negative caution position, the signal 8 will be operated to its caution indicating position, thereby effecting-deenergization of the relay M and reenergization of thel east bound signal indicating lamp EI.

Let us now ass'umethat there isa: west bound train occupying'theside track of the passing siding PS and that the dispatcher. wishes thistrain to proceed into the single track section 0. To accomplish this it will of course be necessary for the dispatcher to operate the track switch SW to its. take-siding position, and this is accomplished by operating thelever WL to its dotted position, through the medium of which 'the relay WZ is energized to its left hand position through a circuit heretofore traced, except that it is now connected to the terminal of the central office split battery. Operation of the relay WZ to its left hand position will effect operation of the switchmachine SM to its take-siding position through the medium .of suitable wires conventionally shown by thedotted line 9.

As soon as the switch machine SMis unlocked (this switch machinepreferably being one of the general type as shown in Howe Patent No. 1,466,903. dated September l, 1923) the switch machine repeater relay WP is deenergized. This deenergization ofthe relay WP will effect dropping of its contact 2-3 thereby changing the polarity applied to the relay OS, so thatthe magnetism in the core structure of the relay OS must pass through zero and effect momentary deenergization of the relay OS, and therefore. of OSR. This momentary deenergization of the relay OS effects momentary flashing of the indicating lamp OSI in the central office, for reasons heretofore given, therebyinforming the dispatcher that. the switch machine has begun its operating stroke. As soon as the switch machine 5 SLto its left hand'position, thereby completing the following energizing circuit for the relay R ':"beginning'at the terminal of the central offi ce battery, contact 92 of the lever SL, wire 93 ,'winding of the relay'R to the other terminal of saidbattery.- This movement of the lever SL will of course efiect de'energization of the'relay R so that the signal control relay-SZ will now be energized to its left hand dotted position through the following circuit:

beginning at the terminal of the central 5 oflice split battery, front contact 95" of the relay R ,'wire 96, back contact 45 of the relay R wire 46, winding of the relay SOS and. elements 41, 48, 49, 50 and 5| through the winding of the relay SZ, to a common return'wire C connected to the midpoint of the olhce split battery.

With the-relay SZ now operated to its left hand position and with relays WZ and WP assuming their left hand position the dwarf starting signal "I is cleared through the following circuit:beginning at the terminal of the way station battery, front contact 53 of the relay DT, elements 54, 55, 5B, 51-, I00, IBI, I02, I93, I84, I35, I06, I01, I08, I09, III! and III, polar contact II2 o f thehome relay IH'through the clear or caution wire conventionally shown by the dotted line H3 to the'dwarf starting signal I The train under consideration may now proceed in response to the clearing of the starting signal E into the single track section 0, and the occupancy of the detector track circuit will again beindicated by the indicating lamp OSI in a manner as already heretofore explained, and-also the fact whether the signal 1 assumes the stop or a proceed position will be indicated through the medium of a west bound traffic light WI, the circuit of which includes the wires I I4 and l i5 and-the front contact II6 of the relay R readily tracedin the drawings.

Attention is particularly directed to the polar contacts of the relay W2 and 66 of relay WP and their-associated wiring, from which is will readily appear that the signal 8 or 8 cannot be cleared unless the contacts 60 and 66 assume like polar positions. In other words, these signals 8 and 8 cannot be cleared unless the position of the switch machine as manifested by the polar position of the relay WP corresponds to the polar position of the relay WZ for controlling this switch machine SM. It is thus apparent that the signals-8 and 8 cannot be cleared unless the switch machine SM has followed a change in the position of the relay WZ. What has been said in regard to contacts 68 and 66 and signals 8 and 8 is also true of the polar contact I92 and IE8 of the relays WP and WZ, respectively, and the signals 1 and I The purpose of this check on correspondence of devices is to check the operativeness of the switch machine, switch points and the like, whereby if the switch fails to-respond to the changeof relay WZ none of the signals can be cleared.

Let us now assume that the apparatus has again been returned to its normal position, as shown in the'drawings, and that the dispatcher decides to clear the; signal I to allow a west bound train to pass from the main track of the passing siding PS into the single track section 0, andin order to do so moves his signal lever SL to its left hand position. This movement of the leVerSL to the left will of course effect energization of the relay R through'the. medium of contact Q5 of which therelay SZ-will be operated to its left hand dotted position, and close the following energizing circuit. for the mechanism of signal 'I:-beginning at the terminal of the way station battery, front. contact 53 of therelay DT, elements 54, 55, 56, 51,. I00, I20, I68, I07, 506, L05; tM;'Ill3,' I112, tZJ, E22 2and I23, polar contact l 24 of the relay TIL-the clearer caution wire conventionally shown by, the. dotted line I25, through the signal mechanism of signal I, to the other terminal of the way station battery. The clearing of the signal 1, assuming traf-, -fic conditions in advance thereof to be favorable, will efiect deenergization of the relay M and dropping [of its contact 48, which in turn will cause the signal relay SZ to be stuck up'through a stick circuit the same as heretofore traced, except that the contact 13 now assumes the left hand dotted position. Clearing of the signal I will of course result in illumination of the indicating lamp'WI for-reasons heretofore given.

Let us now assume that the operator has made a mistake and wishes to again put the signal I to stop. It is readily apparent that the operator cannot deenergize the signal relay 52 through the medium of the line circuit 41, because the contact 48 of the relay M is in its retracted position and has broken this line circuit. The operator will, however, return his signal lever SL to the middle position thereby effecting deenergization of the relay SZ through the medium of the switch machine line wire 38,'as presently explained. Movement of the lever SL to the middle I position will break the energizing circuit for the relay WZ by reason of the fact that the contact 32 of the relay R in the central oflice D0 will drop only a short time after the shunt comprising wires I21, lever SL andwire 86, around this contact 32 is broken, so that the relay WZ is momentarily deenergized, that is, during the time required for the relay R to assume its deenergized position. This momentary deenergization of the relay WZ, due in part to the long wipe stationary contact withwhich control 92 of lever SL cooperates, will momentarily break the stick circuit forthe relay SZ at the front contact 50 of the relay WZ. It will be noted, however, that dropping of the contact 50 of the relay WZ will not effectbreaking of the line circuit 41 under conditions when the contact 48 of the relay M is assuming its energized position, as may at times be the case, because with the contact 50 in its retracted position current may flow through the resistance unit I28 to the common return wire C connected to the midpoint of the central ofiice battery. The resistance unit is a substitute for therelay SZ and therefore its impedance is preferably the same as that of the relay SZ. MO:- mentary breaking of the'stickcircuit for the signal control relay 82 will effect deenergization of this relay SZ, and since the lever SL in the central ofiice DO isv now in its middle position the relaySZ will remain deenergized.

In the same manner, as the delay in the dropping of therelay R has effected momentary deenergization of the switch machinecontrol relay WZ due to movement of the lever'SL from its left hand position to itsmiddle positon as just explained, the slow dropping of the relay R in order that the contact 35 of relay It shall not make its back contact and hence close the circuit for relay WZ, until a short time after the shunt, including wire 81, lever SL, and wire 86, is opened by movement of lever SL to its mid-position will effect momentary deenergization of the switch machine relay WZ due to movement of the signal lever SL from its right hand'to its middle position. In other words, the movement of the signal lever SL from either of its two extreme positions to the middle or the other of its two extreme: positions will effect momentary'breaking of theener= gizing circuit for the switch machine relay WZ,

and this in turn will effect momentary opening of the stick circuit for the signal control relay SZ, so that this signal control relay SZ may be ope erated to its deenergized position .manually through the medium of the control circuit for the switch machine relay WZ, and'this feature of applicants construction permits a signal to be put to stop manually from the central office.

It should be noted that the control circuit for the take-siding signal 8 includes only one trafiic controlled contact, namely contact I30 of the detector track relay DT. This is on the assumption that the side track of the passing siding PS is not track circuited. If the side track is to be track circuited, the signal 8 is controlled in accordance with 'traflic conditions in advance in the same manner as the signal 8 has been shown con trolled. I

Applicant has thus provided an arrangement/of circuits and devices whereby a track switch may be controlled froma local office and four signals associated with said track switch maybe con trolled from the local office through the medium of two direct current polar circuits, and provision has been made whereby the same circuits through the medium 'of the same, current sources may transmit continuing indications to said local oiice of the occupancy of the detector track circuit associated with such track switch, the indicating conditions of signals associated with such track switch and further the initiation and completion of the stroke of the switch machine.

Having thus shown and described one rather. specific embodiment of my present invention, it is desired to be understood that the particular embodiment of the inventionillustrated has not been selected for the purpose of showing the scope of the invention or the exact construction preferably employed in practicing the invention, but has been selected for the purpose of facilitat ing disclosure of the underlying principles of the invention and one arrangement for carrying out these principles, and that various changes, modifications and additions may be made to adapt the invention to the particular problem encountered in practicing the same, all without departing from the spirit or scope of the invention or the idea of means underlying the same, except as demanded by the scope of the following claims.

What I claim as new is:--

1. Signal control and indicating 'means comprising, a distant signal, a relay associated with said signal for controlling said. signal, a local office, a line circuit connecting said relay and ofilce, means for energizing said relay to clear said signal, means for opening said line circuit and" relay energized irrespective of said line circuit,"

means for opening said line circuitin response to clearing of said signal, and means at said office for indicating the continuity of said line circuit.

3. Signal control and indicating meansv comprising, a distant signal, a stick relay associated f' with said signal for controlling said signal, a local oifice, a line circuit connecting said relay and oflice,- means for energizing said relay to 10168.1 said signal, a stick circuit for maintaining'said stick relay energized irrespective of said line circuit, means for opening said line circuit in re sponse to clearing of said signal, means at said office for indicating the continuity of said line circuit, and other means for breaking said stick circuit.

4. Signal control and indicating means com prising, a distant signal, a stick relay associated with said signal for controlling said signal, a local ofiice, a line circuitconnecting said relay and ofiice, means for energizing said relay to clear said signal, a stick circuit for maintaining said stick relay energized irrespective of said line circuit, means for opening said line circuit in response to clearing of said signal, means at said office for indicating the continuity of said line circuit at said signal and in turn the indicating condition of said signal, and other means for breaking'said stick circuit.

5. In combination, a distant track switch, a switch control relay for controlling said track switch, a signal associated with said switch, a signal control'relay for controlling said signal, two line circuits one for controlling said switch control relay and the other for controlling said signal control relay connecting a local office with said track switch location, a stick circuit for .said signal control relay including a source of current at said signal, an indicating relay included in series with each of said line circuits at said office for manifesting the continuity of said line circuits, means for opening the line circuit for said switch control relay upon passage of a train over said track switch, 'means for opening the line circuit for said signal control relay upon clearing of said signal said signal control relay being maintained energized through its stick circuit, and means for breaking said stick circuit upon deenergization of said switch control relay.

6. In combination, a distant track switch, a switch control relay for controlling said track switch, a signal associated with said switch, a signal control relay for controlling said signal, two line circuits one for controlling said switch control relay and the other for controlling said signal control relay connecting a local office with said track switch location, a stick circuit for said signal control relay including a source of current at said signal, an indicating relay included in series with each of said line circuits at said ofiice for manifesting the continuity of said line circuits, means for opening the line circuit for said switch control relay upon passage of a train over said track switch, means for opening the line circuit for said signal control relay upon clearing of said signal, said signal control relay being maintained energized through its stick circuit, and a front contact of said switch machine relay included in said stick circuit.

'7. In combination, a distant track switch, a switch control relay for controlling said track switch, a signal associated with said switch, a signal control relay for controlling said signal, two line circuits one for controlling said switch control relay and the other for controlling said signal control relay connecting a local ofice with said track switch location, a stick circuit for said signal control relay including a source of current at said signal, an indicating relay included in series in the line circuit including said signal control relay, means for opening the line circuit containing said signal control relay upon'clearing of said signal, said signal control relay being maintained energized through its stick circuit, and

means for breaking said stick circuit upon de energization of said switch controlrelay. e

8. In combination, a distant-track switch, a switch control relay for-controlling said track switch, a signal associated with said switch, a

signal control relay for controlling said signal, two line circuits one for controlling said switch control relay and the other for controlling said signal control relay connecting a local ofiice with said track switch location, a stick circuit for said signal control relay including a source of. current at said signal, an indicating relay included in series in the line circuit including said signal control relay, means for opening the line circuit containing said signal control relay upon clearing of said signal, said signal control relay being maintained energized through its stick circuit, and a front contact of said switch control relay included in said stick circuit.

9. In combinatioma local oflice, a.distant way station, atrack switch at said station, a signal associated with said track switch, two line circuits connecting said local office and saidway station, means for controlling operation of said track switch over one of said line circuits, means for controlling said signal through themedium of both of said line circuits means for indicating train occupancy of said track switch over one of said line circuits, and means for indicating the the clearing of said signal over said other line circuit. e

10. In combination, a local oflice, a distant way station, a track switch atsaid way station, a signal associated with said track switch,two line circuits connecting said local office and saidway station, means for controlling operation of said track switch over one of said line circuits, means for controlling said signal through the medium of both of said line circuits, means for distinctively indicating train occupancy of said track switch and operation of said track switch over one of said line circuits, and means for indicating the clearing of said signal over said other line circuit.

11. In combination, a distant location, a control ofiice, two separate line circuits connecting the ofiice with the distant location, a stick device at the distant location picked up over one of the line circuits, a local stick circuit for said stick device, a second device at the distant location energized through the other line circuit, means including said other line circuit for breaking the stick circuit of said stick device, and other means controlled over said one line circuit when said stick device is stuck up.

12. In combination, a distant location, a control office, two line circuits connecting the office with the distant location, a stick relay at the distant location picked up over one of the line circuits, a local stick circuit for said stick relay, a second relay at the distant location energized through the other line circuit, the stick circuit of said stick relay including a front point of said second relay, and other means controlled over said one line circuit when said stick relay is stuck up.

13. In combination, a local ofiice, a distant Way station, a track switch at said station, a signal associated with said track switch, a switch control relay, a signal control relay, two line circuits connecting said local office and said way station including respectively said switch control relay and said signal control relay, the line circuit including said signal control relay also including a front contact of said switch control relay, whereby the operation of said track switch is controlled from one extreme position to the other over one only of said line circuits, and the operation of said signal is controlled through the medium of each of said line circuits separately.

14. In combination, a distant track switch, a switch control relay for controlling said track switch, a signal associated with said track switch, a signal control relay for controlling said signal, two line circuits one for controlling said switch control relay and the other for controlling said signal control relay and both connecting a local oifice with said track switch location, a control lever at the local ofiice for each of said two line circuits, a stick circuit for said signal control relay including a source of current at said signal,

means for energizing said line circuits depending upon the position of said control levers, means for opening the line circuit for said signal control relay and closing its stick circuit upon the clearing of said signal, means for breaking said stick circuit for said signal control relay upondeenergization of said switch control relay, and

a signal control lever at a local oifice, having clearing and stop positions, a switch control lever at a local oflice, a line circuit connecting said signal control lever and saidsignal control relay, a

' line circuitconnecting said switch control lever rent at said signal, means for opening the line circuit for said signal control relay upon clearing said switch control relay upon the movement of said signal control lever from a clearing position to a stop position.

16. In combination, a remote signal for governing railway traific and capable of being cleared or at stop, a signal control relay for controlling said signal, a line circuit connecting a local ofi'ice with said signal control relay, a signal control lever for energizing said line circuit when in a clearing position and for deenergizing said line circuit when in a stop position, means for opening said line circuit for said signal control relay upon the clearing of said signal, a stick circuit for said signal control relay closed when said signal-is cleared, a neutral relay including in series in said line circuit at the local ofiice, indicator lamps selected in accordance with the position of said signal lever and energized only when said neutral relay is deenergized wherebythe actuation of said signal lever to a clearing position fails to enerdeenergizing said neutral relay, and means for breaking said stick circuit of said signal control relay upon the return of said signal lever to'a stop position,

' ROBERT M, PI-IINNEY. 

